[niepce] importer: Rewrote the async listSourceContent

[Hubert Figuière <hub src gnome org>]

commit 9184fe86a6d866b2c5c623848d0cdaeb290baaba
Author: Hubert Figuière <hub figuiere net>
Date:   Mon May 15 00:46:27 2017 -0400

    importer: Rewrote the async listSourceContent

 src/engine/importer/directoryimporter.cpp |   31 +++++++-----------
 src/engine/importer/directoryimporter.hpp |   12 +++----
 src/engine/importer/iimporter.hpp         |   15 +++++----
 src/niepce/ui/dialogs/importdialog.cpp    |   47 ++++++++++++++++++----------
 src/niepce/ui/dialogs/importdialog.hpp    |    8 ++++-
 5 files changed, 62 insertions(+), 51 deletions(-)
---
diff --git a/src/engine/importer/directoryimporter.cpp b/src/engine/importer/directoryimporter.cpp
index dfeb25b..6bb5aaa 100644
--- a/src/engine/importer/directoryimporter.cpp
+++ b/src/engine/importer/directoryimporter.cpp
@@ -1,7 +1,7 @@
 /*
  * niepce - engine/importer/directoryimporter.cpp
  *
- * Copyright (C) 2014-2015 Hubert Figuière
+ * Copyright (C) 2014-2017 Hubert Figuière
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -58,35 +58,28 @@ std::string DirectoryImporter::name() const
   return _("Directory");
 }
 
-bool DirectoryImporter::listSourceContent(const std::string & source)
+bool DirectoryImporter::listSourceContent(const std::string & source,
+                                          const SourceContentReady& callback)
 {
-  auto content =
+  auto files =
     fwk::FileList::getFilesFromDirectory(source,
                                          &fwk::filter_xmp_out);
-  for(const auto & entry : *content)
-  {
-    std::lock_guard<std::mutex> lock(m_content_lock);
-    m_content.push_back(ImportedFile::Ptr(new DirectoryImportedFile(entry)));
-  }
-  return true;
-}
 
-std::list<ImportedFile::Ptr> DirectoryImporter::getSourceContent()
-{
   std::list<ImportedFile::Ptr> content;
+  for(const auto & entry : *files)
   {
-    std::lock_guard<std::mutex> lock(m_content_lock);
-    content = std::move(m_content);
-    m_content.clear();
+    content.push_back(ImportedFile::Ptr(new DirectoryImportedFile(entry)));
   }
-  return content;
+  callback(std::move(content));
+
+  return true;
 }
 
-bool DirectoryImporter::doImport(const std::string & source,
-                                 const file_importer & importer)
+bool DirectoryImporter::doImport(const std::string& source,
+                                 const FileImporter& callback)
 {
   // pretty trivial, we have the source path.
-  importer(source, false);
+  callback(source, false);
 
   // XXX return a real error
   return true;
diff --git a/src/engine/importer/directoryimporter.hpp b/src/engine/importer/directoryimporter.hpp
index 0a31226..b778868 100644
--- a/src/engine/importer/directoryimporter.hpp
+++ b/src/engine/importer/directoryimporter.hpp
@@ -1,7 +1,7 @@
 /*
  * niepce - engine/importer/directoryimporter.hpp
  *
- * Copyright (C) 2014-2015 Hubert Figuière
+ * Copyright (C) 2014-2017 Hubert Figuière
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -36,13 +36,11 @@ public:
 
   std::string name() const override;
 
-  bool listSourceContent(const std::string & source) override;
-  std::list<ImportedFile::Ptr> getSourceContent() override;
+  bool listSourceContent(const std::string & source,
+                         const SourceContentReady& callback) override;
+
   bool doImport(const std::string & source,
-                const file_importer & importer) override;
-private:
-  std::mutex m_content_lock;
-  std::list<ImportedFile::Ptr> m_content;
+                const FileImporter & importer) override;
 };
 
 }
diff --git a/src/engine/importer/iimporter.hpp b/src/engine/importer/iimporter.hpp
index f75bd12..e5f16ff 100644
--- a/src/engine/importer/iimporter.hpp
+++ b/src/engine/importer/iimporter.hpp
@@ -1,7 +1,7 @@
 /*
  * niepce - engine/importer/iimporter.hpp
  *
- * Copyright (C) 2014-2015 Hubert Figuière
+ * Copyright (C) 2014-2017 Hubert Figuière
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -31,21 +31,22 @@ class IImporter {
 public:
   virtual ~IImporter() {}
 
-  /** file importer callback */
-  typedef std::function<void (const std::string&, bool)> file_importer;
 
   /** User visible importer name. */
   virtual std::string name() const = 0;
 
+  /** Source content is ready */
+  typedef std::function<void (std::list<ImportedFile::Ptr>&&)> SourceContentReady;
   /** list the source content and store it. */
-  virtual bool listSourceContent(const std::string & source) = 0;
+  virtual bool listSourceContent(const std::string & source,
+                                 const SourceContentReady& callback) = 0;
 
-  /** get the source content. */
-  virtual std::list<ImportedFile::Ptr> getSourceContent() = 0;
 
+  /** file importer callback */
+  typedef std::function<void (const std::string&, bool)> FileImporter;
   /** perform import from source */
   virtual bool doImport(const std::string & source,
-                        const file_importer & importer) = 0;
+                        const FileImporter & importer) = 0;
 
 };
 
diff --git a/src/niepce/ui/dialogs/importdialog.cpp b/src/niepce/ui/dialogs/importdialog.cpp
index e271065..ea4085b 100644
--- a/src/niepce/ui/dialogs/importdialog.cpp
+++ b/src/niepce/ui/dialogs/importdialog.cpp
@@ -1,7 +1,7 @@
 /*
- * niepce - niepce/ui/importdialog.cpp
+ * niepce - niepce/ui/dialogs/importdialog.cpp
  *
- * Copyright (C) 2008-2015 Hubert Figuière
+ * Copyright (C) 2008-2017 Hubert Figuière
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -55,6 +55,8 @@ ImportDialog::ImportDialog()
     , m_attributesScrolled(nullptr)
     , m_images_list_scrolled(nullptr)
 {
+  m_received_files_to_import.connect(
+    sigc::mem_fun(this, &ImportDialog::append_files_to_import));
 }
 
 ImportDialog::~ImportDialog()
@@ -135,30 +137,41 @@ void ImportDialog::setToImport(const Glib::ustring & f)
         // FIXME this should be the right kind
         m_importer = std::make_shared<eng::DirectoryImporter>();
     }
+
+    eng::IImporter::SourceContentReady source_content_ready =
+      [this] (std::list<eng::ImportedFile::Ptr>&& list_to_import) {
+        {
+          std::lock_guard<std::mutex> lock(this->m_files_to_import_lock);
+          this->m_files_to_import = list_to_import;
+        }
+        this->m_received_files_to_import.emit();
+      };
+
+
+    m_images_list_model->clear();
+    m_files_to_import.clear();
+
     auto importer = m_importer;
     auto source_content =
       std::async(std::launch::async,
-                 [f, importer] () {
-                   return importer->listSourceContent(f);
+                 [f, importer, source_content_ready] () {
+                   return importer->listSourceContent(f, source_content_ready);
                  });
 
     m_folder_path_source = f;
     m_destinationFolder->set_text(fwk::path_basename(f));
     m_directory_name->set_text(f);
+}
 
-    m_images_list_model->clear();
-
-    // XXX this should be an event from the async result instead
-    if (source_content.get()) {
-        auto list_to_import = m_importer->getSourceContent();
-
-        for(const auto & _f : list_to_import) {
-            DBG_OUT("selected %s", _f->name().c_str());
-            Gtk::TreeIter iter = m_images_list_model->append();
-            iter->set_value(m_grid_columns.filename, Glib::ustring(_f->name()));
-            iter->set_value(m_grid_columns.file, std::move(_f));
-        }
-    }
+void ImportDialog::append_files_to_import()
+{
+  std::lock_guard<std::mutex> lock(this->m_files_to_import_lock);
+  for(const auto & f : m_files_to_import) {
+    DBG_OUT("selected %s", f->name().c_str());
+    Gtk::TreeIter iter = m_images_list_model->append();
+    iter->set_value(m_grid_columns.filename, Glib::ustring(f->name()));
+    iter->set_value(m_grid_columns.file, std::move(f));
+  }
 }
 
 }
diff --git a/src/niepce/ui/dialogs/importdialog.hpp b/src/niepce/ui/dialogs/importdialog.hpp
index f399c9e..c02ef0c 100644
--- a/src/niepce/ui/dialogs/importdialog.hpp
+++ b/src/niepce/ui/dialogs/importdialog.hpp
@@ -1,7 +1,7 @@
 /*
  * niepce - niepce/ui/dialogs/importdialog.h
  *
- * Copyright (C) 2008-2015 Hubert Figuière
+ * Copyright (C) 2008-2017 Hubert Figuière
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -26,6 +26,7 @@
 #include <string>
 
 #include <glibmm/refptr.h>
+#include <glibmm/dispatcher.h>
 
 #include "engine/importer/importedfile.hpp"
 #include "fwk/toolkit/gtkutils.hpp"
@@ -83,6 +84,7 @@ private:
     class ImportParam;
 
     void doSelectDirectories();
+    void append_files_to_import();
 
     std::shared_ptr<eng::IImporter> m_importer; // as shared_ptr<> for lambda capture
     Glib::ustring m_folder_path_source;
@@ -100,6 +102,10 @@ private:
     Gtk::IconView *m_gridview;
 
     MetaDataPaneController::Ptr m_metadata_pane;
+
+    Glib::Dispatcher m_received_files_to_import;
+    std::mutex m_files_to_import_lock;
+    std::list<eng::ImportedFile::Ptr> m_files_to_import;
 };
 
 }